3-nitrotyrosine and Huntington-Disease

Reactive oxygen species are generated as a by-product of routine biochemical reactions. However, dysfunction of the antioxidant system or mutations in gene function may result in the elevated production of the pro-oxidant species. Modified endogenous molecules due to chemical interactions with increased levels of reactive oxygen and nitrogen species in the cellular microenvironment can be termed as biomarkers of oxidative stress. 3-Nitrotyrosine is one such promising biomarker of oxidative stress formed due to nitration of protein-bound and free tyrosine residues by reactive peroxynitrite molecules. Nitration of proteins at the subcellular level results in conformational alterations that damage the cytoskeleton and result in neurodegeneration. In this review, we summarized the role of oxidative/nitrosative processes as a contributing factor for progressive neurodegeneration in Alzheimer's disease, Parkinson's disease, Huntington's disease, Lou Gehrig's disease and Prion disease. The selective tyrosine protein nitration of the major marker proteins in related pathologies has been discussed. The alteration in 3-Nitrotyrosine profile occurs well before any symptoms appear and can be considered as a potential target for early diagnosis of neurodegenerative diseases. Furthermore, the reduction in 3-Nitrotyrosine levels in response to treatment with neuroprotective has been highlighted which is indicative of the importance of this particular marker in oxidative stress-related brain and central nervous system pathologies.

Topics: Alzheimer Disease; Amyotrophic Lateral Sclerosis; Biomarkers; Humans; Huntington Disease; Parkinson Disease; Prion Diseases; Tyrosine

Huntington's disease (HD) is a neurodegenerative genetic disorder caused by expansion of polyglutamine repeats in the huntingtin gene and characterised by the loss of striatal and cortical neurons. Few studies to date have focussed on peripheral neurotrophic-factor levels in patients with HD.. To measure plasma NGF levels in Huntington's disease and investigate their correlation with disease intensity.. Nineteen patients with HD and nineteen age- and sex-matched healthy subjects took part in this cross-sectional study. Plasma levels of NGF, BDNF, GDNF, nitrotyrosine, and myeloperoxidase (MPO) were measured; lactate dehydrogenase (LDH) levels were determined and white blood cell (WBC) counts were evaluated.. NGF levels were significantly lower, nitrotyrosine levels were higher and LDH activity was greater in HD patients than in healthy subjects. There was no significant difference in MPO levels or WBC counts, whereas the MPO/WBC ratio was considerably higher in HD patients. The data obtained suggested that biochemical and haematological changes correlated with disease severity.. NGF levels are lower in HD patients than in healthy subjects. However, further research is required to confirm the role of NGF in HD.

Topics: Adult; Biomarkers; Female; Humans; Huntington Disease; Male; Middle Aged; Nerve Growth Factor; Nitrosation; Severity of Illness Index; Tyrosine; Young Adult

Oxidative/nitrosative stress is involved in NMDA receptor-mediated excitotoxic brain damage produced by the glutamate analog quinolinic acid. The purpose of this work was to study a possible role of peroxynitrite, a reactive oxygen/nitrogen species, in the course of excitotoxic events evoked by quinolinic acid in the brain. The effects of Fe(TPPS) (5,10,15,20-tetrakis (4-sulfonatophenyl)porphyrinate iron (III)), an iron porphyrinate and putative peroxynitrite decomposition catalyst, were tested on lipid peroxidation and mitochondrial function in brain synaptic vesicles exposed to quinolinic acid, as well as on peroxynitrite formation, nitric oxide synthase and superoxide dismutase activities, lipid peroxidation, caspase-3-like activation, DNA fragmentation, and GABA levels in striatal tissue from rats lesioned by quinolinic acid. Circling behavior was also evaluated. Increasing concentrations of Fe(TPPS) reduced lipid peroxidation and mitochondrial dysfunction induced by quinolinic acid (100 microM) in synaptic vesicles in a concentration-dependent manner (10-800 microM). In addition, Fe(TPPS) (10 mg/kg, i.p.) administered 2 h before the striatal lesions, prevented the formation of peroxynitrite, the increased nitric oxide synthase activity, the decreased superoxide dismutase activity and the increased lipid peroxidation induced by quinolinic acid (240 nmol/microl) 120 min after the toxin infusion. Enhanced caspase-3-like activity and DNA fragmentation were also reduced by the porphyrinate 24 h after the injection of the excitotoxin. Circling behavior from quinolinic acid-treated rats was abolished by Fe(TPPS) six days after quinolinic acid injection, while the striatal levels of GABA, measured one day later, were partially recovered. The protective effects that Fe(TPPS) exerted on quinolinic acid-induced lipid peroxidation and mitochondrial dysfunction in synaptic vesicles suggest a primary action of the porphyrinate as an antioxidant molecule. In vivo findings suggest that the early production of peroxynitrite, altogether with the enhanced risk of superoxide anion (O2*-) and nitric oxide formation (its precursors) induced by quinolinic acid in the striatum, are attenuated by Fe(TPPS) through a recovery in the basal activities of nitric oxide synthase and superoxide dismutase. The porphyrinate-mediated reduction in DNA fragmentation simultaneous to the decrease in caspase-3-like activation from quinolinic acid-lesioned rats suggests a prevention in the r

Topics: Analysis of Variance; Animals; Behavior, Animal; Blotting, Southern; Brain Injuries; Caspase 3; Caspases; Chromatography, High Pressure Liquid; Corpus Striatum; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Electrophoresis, Agar Gel; gamma-Aminobutyric Acid; Huntington Disease; Lipid Peroxidation; Male; Mitochondria; Motor Activity; Nitric Oxide Synthase; Peroxynitrous Acid; Porphyrins; Quinolinic Acids; Radiation-Sensitizing Agents; Rats; Rats, Wistar; Rotarod Performance Test; Superoxide Dismutase; Synaptic Vesicles; Synaptosomes; Tyrosine

In this study, we have examined the mechanisms involved in pyruvate-mediated neuroprotection against quinolinic acid (QA)-induced striatal damage. QA injection into the striatum caused widespread neuronal damage and extensive areas of lesions in core and penumbra. The involvement of oxidative-mediated striatal damage was suggested by increased expressions of peroxynitrite, marked lipid peroxidation, and formation of DNA oxidative damage products. Administration of pyruvate, a glycolysis end product with antioxidant activity, significantly reduced QA-mediated striatal lesions, neuronal degeneration, and oxidative damage, whereas another energy substrate, lactate, was ineffective against oxidative damage and only partially effective in reducing lesions and neuronal degeneration. Treatment with the iNOS inhibitor aminoguanidine attenuated QA-mediated striatal lesions and reduced oxidative damage, indicating that iNOS activation may be involved in the striatal oxidative damage induced by QA. A role for glial cells in mediating oxidative damage was suggested because pyruvate blocked the expression of iNOS and nitrotyrosine in activated microglia and astrocytes in QA-injected striatum. These data suggest that pyruvate reduces oxidative free radical damage in QA-injected striatum and could have clinical utility in the treatment of Huntington's disease (HD).

Topics: Animals; Disease Models, Animal; Drug Administration Routes; Enzyme Inhibitors; Guanidines; Huntington Disease; Lactic Acid; Male; Neostriatum; Neuroglia; Neuroprotective Agents; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Oxidative Stress; Pyruvic Acid; Quinolinic Acid; Rats; Rats, Sprague-Dawley; Stereotaxic Techniques; Tyrosine

Previous work found that dietary l-arginine alters symptom progression in mice transgenic for Huntington's disease (HD), and that cerebral blood flow (CBF) is abnormal in early stage HD patients. Both of these findings potentially implicate nitric oxide (NO) and its converting enzyme, nitric oxide synthase (NOS), in HD. The current experiment found that both NOS enzymatic activity and neuronal NOS (nNOS) protein expression were reduced (P<0.05) in R6/2 HD transgenic mice compared to non-HD controls (CON). Conversely, inducible NOS (iNOS) protein expression was not significantly different between groups. The changes in nNOS were accompanied by changes in protein expression of calmodulin kinase II (CaMKII) (P<0.05) and calmodulin kinase IV (CaMKIV) (P<0.05). Protein expression of 3-nitrotyrosine (3-NT), a marker for the neurotoxin peroxynitrite, was slightly increased in non-drug treated HD and was accompanied by increased immunostaining of 3-NT in cells adhering to the vasculature and choroid plexus. Mice that received the broad-spectrum NOS inhibitor N(g)-nitro-L-arginine methyl ester hydrochloride (L-NAME) via their drinking water had reduced NOS enzyme activity. NOS activity varied as a function of L-NAME dose, was virtually eliminated in the 500-mg/l groups, and correlated (P<0.05) with the behavioral scores as revealed by regression and correlation analyses. High dose L-NAME (500 mg/l) accelerated symptom onset in HD transgenics. These results support the hypothesis that nNOS activity and NO production are abnormal in HD, this in the setting of a more global dysregulation of calcium protein expression. Taken collectively with earlier data from our laboratory demonstrating abnormal CBF findings in early-stage HD patients, these results suggest that abnormalities in NOS function may significantly contribute to the neurodegeneration found in HD.

Topics: Animals; Behavior, Animal; Body Weight; Brain; Calcium-Calmodulin-Dependent Protein Kinases; Disease Models, Animal; Enzyme Inhibitors; Female; Huntington Disease; Immunohistochemistry; Male; Mice; Mice, Transgenic; Motor Activity; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Tyrosine

Glutathione peroxidase (GSHPx) is a critical intracellular enzyme involved in detoxification of hydrogen peroxide (H(2)O(2)) to water. In the present study we examined the susceptibility of mice with a disruption of the glutathione peroxidase gene to the neurotoxic effects of malonate, 3-nitropropionic acid (3-NP), and 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Glutathione peroxidase knock-out mice showed no evidence of neuropathological or behavioral abnormalities at 2-3 months of age. Intrastriatal injections of malonate resulted in a significant twofold increase in lesion volume in homozygote GSHPx knock-out mice as compared to both heterozygote GSHPx knock-out and wild-type control mice. Malonate-induced increases in conversion of salicylate to 2,3- and 2, 5-dihydroxybenzoic acid, an index of hydroxyl radical generation, were greater in homozygote GSHPx knock-out mice as compared with both heterozygote GSHPx knock-out and wild-type control mice. Administration of MPTP resulted in significantly greater depletions of dopamine, 3,4-dihydroxybenzoic acid, and homovanillic acid in GSHPx knock-out mice than those seen in wild-type control mice. Striatal 3-nitrotyrosine (3-NT) concentrations after MPTP were significantly increased in GSHPx knock-out mice as compared with wild-type control mice. Systemic 3-NP administration resulted in significantly greater striatal damage and increases in 3-NT in GSHPx knock-out mice as compared to wild-type control mice. The present results indicate that a knock-out of GSHPx may be adequately compensated under nonstressed conditions, but that after administration of mitochondrial toxins GSHPx plays an important role in detoxifying increases in oxygen radicals.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; 3,4-Dihydroxyphenylacetic Acid; Animals; Brain Chemistry; Catechols; Convulsants; Corpus Striatum; Disease Models, Animal; Dopamine Agents; Female; Free Radicals; Glutathione; Glutathione Peroxidase; Heterozygote; Homovanillic Acid; Homozygote; Huntington Disease; Male; Malonates; Mice; Mice, Inbred Strains; Mice, Knockout; MPTP Poisoning; Nitro Compounds; Oxidative Stress; Parkinson Disease, Secondary; Propionates; Tyrosine

Recent neuroimaging studies reported complex changes in cerebral blood flow (CBF) in early-staged Huntington's disease (HD) patients. Deckel and co-workers [Deckel and Duffy, Brain Res. (in press); Deckel and Cohen, Prog. Neuro-Psychopharmacol. Biol. Psychiatry 24 (2000) 193; Deckel et al., Neurology 51 (1998) 1576; Deckel et al., J. Nucl. Med. 41 (2000) 773] suggested that these findings might be accounted for, in part, by alterations in cerebral nitric oxide (NO) and its byproduct, peroxynitrite. The current experiment tested this hypothesis by altering NO levels via manipulations of dietary L-arginine (ARG), the dietary precursor of NO, in mice transgenic for HD. Seventy-one mice were assigned at 12 weeks of age to one of three isocaloric diets that varied in their content of ARG. These diets included: (a) 0% ARG, (b) 1.2% ARG (i.e. typical mouse chow), or (c) 5% ARG. The 5% ARG diets in HD mice accelerated the time of onset of body weight loss (P<0.05) and motor impairments (P<0.05), and increased resting CBF in HD relative to control (P<0.05). Conversely, the 0% ARG diet demonstrated no loss of body weight and had no changes in CBF relative to controls. However, the 0% ARG HD group continued to show significant deficits on motor testing (P<0. 05). The 1.2% ARG HD group showed reduced body weight loss, better motor functioning, and fewer changes in CBF compared to the 5% ARG HD group. Immunocytochemistry analysis found greater deposition of nitrotyrosine in the cortex, and vasculature, of HD+ mice, 5% and 1. 2%>0% arginine diets. When collapsed across all conditions, CBF inversely correlated (P<0.05) both with the body weight and motor changes suggesting that changes in CBF are associated with behavioral decline in HD mice. Collectively, these findings indicate that dietary consumption of the NO precursor ARG has a measurable, but complex, effect on symptom progression in HD transgenic mice, and implicates NO in the pathophysiology of HD.

Topics: Animals; Arginine; Blood Glucose; Brain; Cerebrovascular Circulation; Diet; Huntington Disease; Mice; Mice, Transgenic; Movement Disorders; Time Factors; Tyrosine; Weight Loss

The gene defect in Huntington's disease (HD) may result in an impairment of energy metabolism. Malonate and 3-nitropropionic acid (3-NP) are inhibitors of succinate dehydrogenase that produce energy depletion and lesions that closely resemble those of HD. Oral supplementation with creatine or cyclocreatine, which are substrates for the enzyme creatine kinase, may increase phosphocreatine (PCr) or phosphocyclocreatine (PCCr) levels and ATP generation and thereby may exert neuroprotective effects. We found that oral supplementation with either creatine or cyclocreatine produced significant protection against malonate lesions, and that creatine but not cyclocreatine supplementation significantly protected against 3-NP neurotoxicity. Creatine and cyclocreatine increased brain concentrations of PCr and PCCr, respectively, and creatine protected against depletions of PCr and ATP produced by 3-NP. Creatine supplementation protected against 3-NP induced increases in striatal lactate concentrations in vivo as assessed by 1H magnetic resonance spectroscopy. Creatine and cyclocreatine protected against malonate-induced increases in the conversion of salicylate to 2,3- and 2,5-dihydroxybenzoic acid, biochemical markers of hydroxyl radical generation. Creatine administration protected against 3-NP-induced increases in 3-nitrotyrosine concentrations, a marker of peroxynitrite-mediated oxidative injury. Oral supplementation with creatine or cyclocreatine results in neuroprotective effects in vivo, which may represent a novel therapeutic strategy for HD and other neurodegenerative diseases.

Topics: Adenosine Triphosphate; Animals; Antihypertensive Agents; Antineoplastic Agents; Creatine; Creatinine; Disease Models, Animal; Energy Metabolism; Free Radicals; Huntington Disease; Lactates; Male; Malonates; Neostriatum; Neuroprotective Agents; Neurotoxins; Nitro Compounds; Oxidative Stress; Propionates; Rats; Rats, Sprague-Dawley; Tyrosine

Nerve growth factor (NGF)-secreting fibroblasts are able to protect against the Huntington-like striatal neurodegeneration induced by the mitochondrial toxin 3-nitropropionic acid (3-NP). In the present study, we investigated whether the neuroprotective effects of NGF are mediated through antioxidative mechanisms. Rats were grafted in the corpus callosum with NGF[+] or NGF[-] fibroblasts 7 days before administration of 3-NP. The generation of peroxynitrite was evaluated by measuring the striatal levels of 3-nitrotyrosine. NGF significantly decreased the 3-NP induced generation of 3-nitrotyrosine, presumably by decreasing peroxynitrite formation. These findings suggest that NGF might protect against neuronal death by inhibiting the production of nitric oxide or decreasing the levels of superoxide radicals, thereby decreasing the generation of oxidative agents such as peroxynitrite.

Topics: Animals; Corpus Striatum; Disease Models, Animal; Huntington Disease; Male; Nerve Growth Factors; Nitro Compounds; Propionates; Rats; Rats, Sprague-Dawley; Tyrosine